Display screen or portion thereof for a transitional graphical user interface



FIG. 1 is a front view of a first image in a sequence for a display screen or portion thereof for a transitional graphical user interface, showing my new design;

FIG. 2 is a front view of a second image thereof;

FIG. 3 is a front view of a third image thereof;

FIG. 4 is a front view of a fourth image thereof;

FIG. 5 is a front view of a fifth image thereof;

FIG. 6 is a front view of a sixth image thereof;

FIG. 7 is a front view of a seventh image thereof;

FIG. 8 is a front view of an eighth image thereof;

FIG. 9 is a front view of a ninth image thereof;

FIG. 10 is a front view of a tenth image thereof;

FIG. 11 is a front view of an eleventh image thereof;

FIG. 12 is a front view of a twelfth image thereof;

FIG. 13 is a front view of a thirteenth image thereof;

FIG. 14 is a front view of a fourteenth image thereof;

FIG. 15 is a front view of a fifteenth image thereof; and,

FIG. 16 is a front view FIG. 1 which illustrates an example environment.

The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1 through 15. This process or period forms no part of the claimed design. The long and short dashed broken line showing of a mobile terminal in FIGS. 1 through 15 forms no part of the claimed design. The mobile terminal, display screen, and the text, numbers, symbols and images of the graphical user interface shown in broken line in FIGS. 1 through 16 depict subject matter that forms no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof for a transitional graphical user interface, as shown and described. 